The best one I ever got was stupidly simple: "pay yourself first, before the bills, before the fun, before anything", and the person who told me meant it literally, as in the moment your paycheck hits you move a fixed amount to savings before you even look at your balance, because the money you never see you never miss and you stop building your life around whatever's left over after everyone else gets paid first. Took me an embarrassingly long time to actually do it, but once I did it became the only financial habit that actually stuck without requiring constant willpower.